Leonardus

From Wikipedia, the free encyclopedia
This article is about the fossil mammalian genus. For the given name, see Leonardus (name).

Leonardus
Temporal range: Late Santonian-Maastrichtian
~84–66 Ma
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Superorder: †Dryolestoidea
Order: †Dryolestida
Clade: †Meridiolestida
Family: †Leonardus
Bonaparte 1990
Type species
Leonardus cuspidatus
Bonaparte 1990

Leonardus is an extinct mammal genus from the Late Cretaceous (Late Santonian to Maastrichtian) of South America.[1] It is a meridiolestidan dryolestoid, closely related to the also Late Cretaceous Cronopio and the Miocene Necrolestes.[2][3]

Description[]

Leonardus is a fairly small mammal, similar in size to Necrolestes. It is known from two specimens, the holotype MACN-RN 172, composed of a left maxilla, four associated molariform teeth and two pairs of alveoli, and MACN-RN 1907, a right mandible with two molariforms. Said molariforms are vaguely peg-like, with a dome-like stylocone.

Discovery[]

Leonardus is currently only known from the Los Alamitos Formation, Argentina. The holotype was found in 1990, while the second specimen was described more recently in 2010.

Classification[]

Leonardus was originally referred to Dryolestidae, but the lack of a parastylar hook on the molariforms, as well as a few features of the stylocone, suggest that it was grouped with other South American and African dryolestoids at the exclusion of Laurasian species, in a clade known as Meridiolestida.[4] Within Meridiolestida, it consistently groups with Necrolestes and Cronopio.[2][3]

Paleobiology[]

Leonardus' teeth are noted as being unique among dryolestids and the animal would have had an orthal and transverse jaw-stroke with tooth-to-tooth shearing,[4] though no further comments have been made on its diet.

References[]

  1. ^ Leonardus at Fossilworks.org
  2. ^ a b Guillermo W. Rougier, John R. Wible, Robin M. D. Beck and Sebastian Apesteguía (2012). "The Miocene mammal Necrolestes demonstrates the survival of a Mesozoic nontherian lineage into the late Cenozoic of South America". Proceedings of the National Academy of Sciences of the United States of America. 109 (49): 20053–20058. doi:10.1073/pnas.1212997109.
  3. ^ a b Alexander O. Averianov, Thomas Martin and Alexey V. Lopatin (2013). "A new phylogeny for basal Trechnotheria and Cladotheria and affinities of South American endemic Late Cretaceous mammals". Naturwissenschaften. 100 (4): 311–326. doi:10.1007/s00114-013-1028-3.
  4. ^ a b Laura Chornogubsky, New remains of the dryolestoid mammal Leonardus cuspidatus from the Los Alamitos Formation (Late Cretaceous, Argentina), Article in Paläontologische Zeitschrift 85(3):343-350 · September 2011 DOI: 10.1007/s12542-010-0095-4
Retrieved from ""